Solar Cells and Integration of Nanotechnology

• Organic/Inorganic solar cells• Silicon solar cells are most common

and efficient right now.• Reflection of incoming light is a big

natural limitation for efficiency.

Konarka

Evergreen Solar, Inc. Marlboro, MA

Top side metallization grid

Sunlight

0.5 µm

n+ emitte

r

Average phosphorus~1018cm-3

~100-300 µm

Boron~1016cm-3

p base

Optional p+ back surface diffusionBack side metalliza

tion

Typical P-N Junction Silicon Solar Cell Structure

REFLECTION!

Anti-reflection coating

Pattern Transfer by Etching (Tunable Anti-Reflective Coating)

J. Vac. Sci. Technol. B 20.6., Nov. Dec 2002

UMASS

Can work as an anti-reflective coating!

Single Cell

Vout~0.5 Volts

Cut cells connected in series

Vout~3 Volts

Single Cell vs. Cut Cells

Electrical Measurements

Maximum power rectangle

VocVmax

Imax

Isc

FF VmaxImaxIscVoc

Dist.

I V I.V